1. Field of the Invention
The present invention generally relates to bicycles. More particularly, the present invention relates to a seat tube configured to reduce vibrations transmitted to a rider of the bicycle.
2. Description of the Related Art
Bicycle riding and racing often takes place on less than ideal terrain conditions. For example, bicycle touring and racing may often take place on country roads, which may be unpaved or where the pavement may be rough and irregular, even when new. In more populated areas, a significant portion of paved roads may be damaged and in need of repair. When traversed by the bicycle, these irregular surfaces transmit vibrations to the bicycle. Furthermore, the surface of even relatively new pavement, while acceptable for motor vehicles, may be rough enough to transmit significant vibration to a bicycle. Accordingly, most bicyclists spend at least a significant portion of their riding time traversing rough or irregular surfaces. Vibrations induced by such terrain, if not sufficiently dampened, may be transmitted to the rider of the bicycle. When transmitted to the rider, these vibrations often cause discomfort and fatigue.
Several methods for damping terrain-induced vibrations have been utilized. For example, the bicycle may be equipped with front and/or rear suspension assemblies, which permit the suspended wheel to move against a biasing force relative to the bicycle frame. Although highly favored in some applications, such as bicycles intended primarily for off-road use, such suspension assemblies have generally been unsuccessful in connection with bicycles primarily intended for use on paved surfaces (i.e., road bicycles), where low weight and aerodynamics are considered highly important. Furthermore, such suspension assemblies are intended to absorb large bumps and may not be effective at isolating vibrations due to inherent friction within the assembly, which may prevent movement of the suspension assembly in response to small forces.
In road bicycle applications, it has recently become popular to utilize materials having improved damping properties in comparison to metals to form a portion or all of the bicycle between the wheels and the rider. For example, a composite material of carbon fiber fabric within a resin matrix (“carbon fiber”) is often used in an attempt to isolate road-induced vibrations from the rider of the bicycle. In some instances, the entire frame of the bicycle may be comprised of a carbon fiber material.
Such an arrangement has been more successful in isolating terrain-induced vibrations from reaching the rider of the bicycle in comparison with bicycle frames and components comprised entirely of metal. However, although carbon fiber is lightweight and exhibits improved vibration damping characteristics in comparison to metal, a significant amount of vibration may nonetheless be transferred through components made from carbon fiber.